winflex 2006 - mechanistic empirical overlay design system for flexible pavement

Download WINFLEX 2006 - Mechanistic Empirical Overlay Design System for Flexible Pavement

Post on 30-Oct-2014

71 views

Category:

Documents

0 download

Embed Size (px)

TRANSCRIPT

Included

CD

Mechanistic-Empirical Overlay Design System for Flexible Pavement

Technical Background for Program DevelopmentFinal Report of Project No. KLK492 ITD Contract No. SPR-0010 (028), RP 121

Prepared for Idaho Transportation Department

By Fouad M. Bayomy Principal Investigator

Center for Transportation Infrastructure (CTI) National Institute for Advanced Transportation Technology (NIATT) University of Idaho

WINFLEX 2006A Mechanistic-Empirical Overlay Design System For Flexible Pavement

FinalSubmittalThe final submittal of this project includes: 1. CD for the Software, which includes the WINFLEX 2006 software setup package, help manual, and set of design examples, 2. Two DVDs for video presentations on program training; and 3. This report on the program documentation.

UI Research Team Fouad M. Bayomy, PhD, PE Professor of Civil Engineering, and Principal Investigator, National Institute for Advanced Transportation Technology (NIATT) University of Idaho Moscow, ID 83844-1022 Bayomy@uidaho.edu Steve J. Taylor Programmer Analyst National Institute for Advanced Transportation Technology (NIATT) University of Idaho Moscow, ID 83844-0901 Staylor@uidaho.edu

ITD Project Coordinator Michael J. Santi, PE Assistant Materials Engineer Idaho Transportation Department PO Box 7129 Boise, ID 83707-1129 Mike.Santi@itd.idaho.gov

WINFLEX Program Documentation Page i

TABLE OF CONTENTS Chapter 1 - Introduction ...................................................................................................... 1 1.1 General ...................................................................................................................... 1 1.2 Project History .......................................................................................................... 1 1.3 Project Objective ....................................................................................................... 1 Chapter 2 Background of the Overlay Design Procedure in WINFLEX 2006................ 2 2.1 General ...................................................................................................................... 2 2.2 Pavement Structure Model........................................................................................ 2 2.3 Design Inputs ............................................................................................................ 3 2.3.1. Material Properties ............................................................................................ 3 2.3.2. Traffic Data ....................................................................................................... 5 2.3.3. Environmental Effects ...................................................................................... 5 2.4 Pavement Response ................................................................................................ 20 2.5 Allowable Traffic and Failure Criteria ................................................................... 21 2.5.1. Fatigue Failure ................................................................................................ 21 2.5.2. Rutting Failure ................................................................................................ 23 2.6 Damage Analysis .................................................................................................... 23 2.6.1. For Fatigue ...................................................................................................... 24 2.6.2. For Rutting ...................................................................................................... 24 Chapter 3 Description of WINFLEX User Interface ..................................................... 25 3.1 General .................................................................................................................... 25 3.2 WINFLEX Screens ................................................................................................. 25 Appendix A References ................................................................................................. 31 Appendix B Description of Forms and Modules in WINFLEX 2006 ........................... 34 General WINFLEX 2006 Forms ............................................................................... 34 Main User Forms ...................................................................................................... 36 WINFLEX 2006 Modules......................................................................................... 37 Appendix C Examples of Output Reports ..................................................................... 38 Example of Output of a Single-Location Design ...................................................... 38 Example of Output of a Multiple-Location Design .................................................. 40

WINFLEX Program Documentation Page ii

LIST OF FIGURES Figure 1. Idaho Pavement Climate Zones [Ref. 11] ....................................................... 7 Figure 2. Adjustment Factor for Subgrade Freezing [Ref. 11] ...................................... 9 Figure 3. Adjustment Factor for Subgrade Thawing [Ref. 11] .................................... 10 Figure 4. Winter-Spring Temporary Water Content Increase [Ref. 11] ...................... 11 Figure 5. Adjustment Factors for Post-Construction W.C. Increase [Ref. 11] ............ 11 Figure 6. Graphical Representation of Subgrade Modulus Variations Throughout the Year for Pavement Climate Zones in Idaho .............................................................. 14 Figure 7. SHRPs Equation for Conventional Asphalt Mixes...................................... 18 Figure 8. Schematic of the Modulus-Temperature Adjustment ................................... 19 Figure 9. Fatigue Models Used by Various Agencies .................................................. 22 Figure 10. Rutting Models Used by Various Agencies .............................................. 24

LIST OF TABLES

Table 1. Poisson ratios for paving materials [Ref. 5] ......................................................... 3 Table 2. Environmental Parameters Representing Climatic Zones in Idaho ...................... 8 Table 3. Seasonal Adjustment Factors (SAF) for Idaho Climatic Zones [Ref. 16] .......... 17 Table 4. Fatigue and Rutting Coefficients Used by Various Agencies ............................ 23

WINFLEX Program Documentation Page iii

Chapter 1 - Introduction1.1 GeneralThe purpose of this brief report is to document the technical background of the development of the WINFLEX 2006 software. It describes the engineering principals used in the development of the mechanistic-empirical overlay design system that is implemented in the WINFLEX software.

1.2 Project HistoryThe development of this computer program was performed through a series of contracts with ITD. The first contract (Research Project RP 121, Agreement No. 95-60) dealt with the system development and its implementation in computer software. The first version of the software was DOS-based due to the fact that Fortran computer language was only available in the DOS environment. The first version of the program was named FLEXOLAY. It was developed using two computer languages - Fortran 77 and Visual Basic for DOS. It was released in 1996. Shortly after Microsoft release of the Fortran Power Station 4.0 for Windows, an upgrade of the FLEXOLAY program to operate under Windows was requested by ITD. Hence, the first windows-based program (WINFLEX 97) was developed under ITD project RP 121 Phase. The upgrade included not only the transfer to a new computer environment, but also included new design features in the program. For example, FLEXOLAY could only design an overlay for a single pavement section, while WINFLEX 97 can design overlay for multiple pavement sections at the same run. The next release of WINFLEX was developed under Windows 2000 operating system. The WINFLEX 2000 was developed under NIATT project No. KLK456 and has been included in the ITD materials manual. It contained two main codes using two computer languages - Visual Basic 6.0 and Fortran Power Station 4.0. The latest version is the WINFLEX 2006, which was initiated under NIATT project No. KLK492. It built on the WINFLEX 2000 and addressed many programming bugs that were discovered during the previous several years.

1.3 Project ObjectiveThe main objective of this project was to upgrade the WINFLEX 2000 software to add features and resolve many bugs that were discovered in the 2000 version. In addition, a training workshop was developed and delivered to ITD. A set of two video DVDs were also developed for training purpose.

WINFLEX Program Documentation Page 1

Chapter 2 Background of the Overlay Design Procedure in WINFLEX 20062.1 GeneralThe mechanistic-empirical (M-E) design concept is not new to pavement design engineers and has been addressed in hundreds of publications over decades. A list of slected references is provided in Appendix A. [ Ref 1 to 31]. The M-E overlay design procedure requires the determination of critical stresses, strains and deflections in the pavement by some mechanistic methods such as multi-layer elastic theory. Then, empirical models are used to evaluate the pavement accumulated damage or failure in various distress modes. The design decision would be based on some empirical failure criteria. To implement this methodology in overlay design, the condition of the existing pavement must be evaluated first to assess the bearing capacity and the structural condition of the existing pavement section. Based on the anticipated future traffic and the adopted failure criteria, the remaining life of the exiting pavement is assessed. Hence, a decision is made on whether an overlay is needed and how much overlay thickness is

Recommended

View more >